A virus spreads around and usually attaches itself to the host, multiplies & causes diseases. But is there something like an anti-virus? A single celled entity that does the opposite: spreads around 'kills' other viruses and/or cures diseases. Has anybody discovered something like it or is there any research group working on synthesizing one? If so any links to their publications? Forgive me if I got my facts wrong, I am physical sciences person and know nothing about biology. :)
There is no anti-virus to all viruses and there is no such anti-virus against a single virus yet, but there is immune response to virus. How efficient the immune response is then depends on many things. There is no perfect immune response. To develop such an antivirus that decreases viral load requires cooperation with the immune response. To develop such an antivirus is still in very very early stages, since we do not understand the fine regulation of many processes going on in the viral pathogenesis and how to stop them.
The immune response tries to eliminate the virus through antigen presentation and cell-mediated immune response. The humoral immune response works in the local sides where the cell mediated immune response does not reach. However, the immune response is sometimes (and often) insufficient to kill the virus.
To develop such a general anti-virus is difficult because of a variety of different viruses: (RNA vs DNA; positive sense vs negative sense; single strained vs double stranded; intracellular replication vs extracellular).
Here is an example of antigen presentation for HIV virus deduced from this answer:
where HIV infects the antigen presentation cells (APC) (dendritic cell and macrophages) and monocytes. It replicates actively in the lymphatic circulation. Since APCs are out, it is difficult to kill the virus. To develop such a general anti-virus against HIV would require very specific understanding of many things: probably, iPS cells and development of antigen presentation cells. My conjuncture is to develop an APC cell that has receptor to HIV virus and so can reach it. However, only theory.
Gamma interferon should be included in the intersection between innate and adaptive immune systems. Interferons may play a central role in the future in the development of such anti-viral drugs, because they are specific. For instance, the activation of IFN-gamma stimulates the phagocytosis of macrophages against the mycobacteria tuberculosis which is facultatively intracellular (can be intracellular when necessary).
Innate and adaptive immune systems are visualised on the plane in the figure. You have then humoral immunity working around that plane as circles. I emphasize with that the local nature of humoral immune system and how it extends the cell-mediated immune system. Any attack on the heart of this system i.e. antigen presentation will also risk the humoral immunity and thus cause fast progression of the disease.
In summary, all measures that are used to decrease the viral load aim to target the immune system to express efficient way of decreasing the viral load (killing is just one of them!). This can be done through many ways - most of which we do not know much yet. iPS stem cell research and interferon research can be some good ways in the development of good anti-virals. However, this will take still many years (probably at least 40-50 years) to have enough control of the specific viral pathways.